Description: in-line six, overhead valve (two per cylinder), flat-face followers, hydraulic lifters, cast iron block and head
Displacement: 3960 cc (242 cubic inches)
Bore and stroke 98.4 mm x 86.7 mm
Compression ratio 8.8:1
Redline: 5,300 rpm
Maximum power, 2003, Wrangler:
- USA - 190 hp (142kW)@4,600 rpm; 235 lb-ft (319 Nm) @ 3,200 rpm
- Europe - 130 kW (177 hp) @ 4600 rpm; 296 N·m @ 3500 rpm
Fuel injection (final form): sequential multiple-port, electronic
In the Wrangler, 0-60 in 9.9 seconds (manual; 10.6 seconds, four-speed automatic); top speed 108 mph
| European fuel economy (litres / 100KM) | Manual | Automatic |
| Combined cycle | 13.2 | 15 |
| Ex-urban cycle | 9.0 | 10.7 |
| Combined CO2 | 315 g/km | 362 g/km |
| USA (EPA) fuel economy | | |
| City | 15 | 14 |
| Highway | 18 | 18 |
Built in Kenosha, Wisconsin (5555 30th Avenue) - the plant also made the 2.7 and 3.5 liter engines at the same time. In 2003, it could make 405,673 4.0 engines per year (as well as 315,638 2.7s and 220,000 3.5s). The plant was built in 1917!